Acute streptococcal myopericarditis mimicking myocardial infarction

A 25-year-old man who had recurrent sore throats presented with sharp central chest pain 5 hours after starting penicillin for tonsillitis. Electrocardiogram (ECG) revealed ST-segment elevation in leads I and aVL with reciprocal ST depression in lead III (Fig. 1). Troponin I was measured as 33 microg/L (normal range, b0.1 microg/L), and C-reactive protein (CRP) was 127 (normal range b10). Echocardiogram revealed a nondilated well-contracting left ventricle, and cardiac catheterization revealed normal coronary arteries. A diagnosis of acute myopericarditis was made, and he was treated with moxifloxacin. Throat swabs grew Lancefield group A Streptococcus. Over subsequent days, his symptoms and ECG changes resolved, and he was discharged on longterm prophylactic penicillin.